CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Income Statement [Abstract]
Revenues	$ 250.4	$ 305.9
Cost of sales	195.4	233.0
Selling, general and administrative expense	36.0	28.0
Equity in earnings of unconsolidated ventures	(0.6)	0.0
Interest and other income	(2.3)	(6.3)
Income before income taxes	21.9	51.2
Income tax expense	5.4	13.0
Net income	$ 16.5	$ 38.2
Basic net income per common share	$ 0.32	$ 0.76
Weighted average number of common shares	50,820,797	50,065,832
Diluted net income per common share	$ 0.32	$ 0.76
Adjusted weighted average number of common shares	51,085,919	50,462,082